Flake ice machine

ABSTRACT

The invention relates to a flake ice machine, comprising an evaporating cylinder ( 1 ) and an evaporating pan ( 2 ), wherein a sensor is provided to monitor the filling time of the evaporating pan ( 2 ), the production of ice and the water level of the water bath ( 3 ) available in the evaporating pan ( 2 ).

BACKGROUND OF THE INVENTION

The invention concerns a flake ice machine having a cylindricalevaporating cylinder, a transmission or transmission motor with electricdrive (electric motor) for the evaporating cylinder, a refrigerator,also driven electrically, which guides the cooling means through theevaporating cylinder, an evaporating pan, which can be filled withwater, the evaporating cylinder disposed in the evaporating pan in arotatable manner for wetting the evaporating cylinder with water, aswell as means for removing (peeling off or flaking off) the flake icefrom the circumference of the evaporating cylinder, and electric controlmeans for the evaporating cylinder and refrigerator drives.

Flake ice machines of this type produce relatively thin flake ice forkeeping food fresh, particularly in the meat industry.

A conventional flake ice machine of this kind (DE 41 08 911 A1, EP 535498 A2) comprises an evaporating cylinder moistened by inserting oneside thereof into an evaporating pan filled with water. The evaporatingcylinder is turned and residual water freezes on the circumference ofthe evaporating cylinder. The ice layer thereby generated is removedfrom the circumference of the evaporating cylinder by a device disposedat the cylinder, before renewed dipping into the water. This is doneeither by peeling off or by flaking off the ice. The evaporatingcylinder contains a cooling evaporator which is connected to arefrigerator disposed outside the cylinder. The refrigerator ispreferably a compressor-driven machine. In any event, the refrigeratorand the evaporating cylinder drive are controlled electrically via anelectric control means. The filling time, the ice production and thewater level in the evaporating pan are monitored by the control means toprevent damage to the flake ice machine due to defects in e.g. theevaporating cylinder or refrigerator drives or the water supply. Shouldthe monitored quantities exceed or fall below the predetermined limitingvalues, the evaporating cylinder and the refrigerator drives areswitched off. The control means comprises several sensors formonitoring. One sensor checks the thickness of the ice layer on thecircumference and therefore the ice production. Another sensor detectsthe water level in the evaporating pan and an additional sensor monitorsthe filling time of the evaporating pan. Each sensor provides a measuredvalue which has to be processed by the control means and compared withthe predetermined limiting values. Disadvantageously, these conventionalflake ice machines are demanding and expensive to manufacture due to thenumber of sensors and the corresponding control means.

SUMMARY OF THE INVENTION

In contrast thereto, the flake ice machine according to the inventionhas the advantage that only one sensor is provided to signal the controlmeans for the evaporating cylinder and the refrigerator, to control thefilling time of the evaporating pan, the ice production and the waterlevel in the evaporating pan. The measured value to which the sensorreacts is thereby selected in such a manner that it is sensitive to thefilling time, the thickness of the ice layer on the evaporating cylinderand to the water level in the evaporating pan. The control means checkswhether the measured values detected by the sensor are withinpredetermined limits and whether or not the measured values havechanged. The limiting values are selected by taking into considerationvalues for the filling time, the thickness of the ice layer and thewater level which are not critical to proper operation of the flake icemachine. If a measured value exceeds the predetermined limiting value,the refrigerator and evaporating cylinder drives are switched off by thecontrol means before the flake ice machine could be damaged.

According to an advantageous embodiment of the invention, the measuredvalue detected by the sensor is the change of the water level in theevaporating pan over time. If the water level does not change within apredetermined time period of e.g. 60 seconds or if its change exceeds apredetermined limiting value, the evaporating cylinder and refrigeratordrives are switched off after this time period has elapsed. Should e.g.the water supply be interrupted, water can no longer flow and the waterlevel drops below the predetermined limiting value within thepredetermined time period. This causes the flake ice machine to switchoff. If either the evaporating cylinder or the refrigerator drive fails,ice production stops and the water level does not change. This alsoleads to switch-off of the flake ice machine. Should the evaporatingcylinder freeze as a result of an excessively low supply temperature,the water level does not change within the time period. This also leadsto switch-off of the flake ice machine after elapse of the time period.In the most unfavorable case, all of the liquid in the evaporating panfreezes. In this case, the sensor fails to provide measured values andswitch-off of the flake ice machine is also triggered after thepredetermined time period has elapsed. In an advantageous manner,monitoring of the changes in the water level over time begins with adelay with respect to the start of operation of the refrigerator. Thedelay may vary, depending on the type of flake ice machine. A typicalvalue is e.g. 120 seconds. The monitoring control is transitionoperated.

According to a further advantageous embodiment of the invention, thesensor comprises a floating switch provided on the evaporating cylinder.Advantageously, floating switches are independent of the chemical andphysical properties of the freezing liquid used. Therefore, there aree.g. no conductance-related problems when the ice is produced fromdistilled water. Moreover, should the floating switch be defective duee.g. to a broken cable, contact can no longer be interrupted orestablished, wherein no change in the water level within thepredetermined time period is detected and the flake ice machine istherefore switched off.

Further advantages and advantageous embodiments of the invention can beextracted from the following description, the drawing and the claims.

An embodiment of the invention is shown in the drawing and is describedin more detail below.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a flake ice machine according to the invention comprising afloating switch.

FIG. 2 shows a schematic front view of the flake ice machine inaccordance with the invention.

An evaporating cylinder 1 is rotatably supported in an evaporating pan 2of a flake ice machine and is driven in a rotating manner by an electricor transmission motor 10. The lower part of the evaporating cylinder 1is inserted into a water bath 3 such that the circumference 4 of theevaporating cylinder 1 is wet with water during rotation. The waterfreezes on the circumference 4 of the evaporating cylinder 1, which hasbeen cooled by the refrigerator 11. A thin ice layer is thereby formed,which is removed from the circumference by a stationary ice scraper 5and fed to a collecting container (not shown). The evaporating cylinderdrive 10, the refrigerator 11, and the refrigerator 11 drive areconventional units, driven by electric motors. A floating switch 6 isdisposed on a side of the evaporating pan 2 and is inserted into thewater bath 3. The floating switch detects changes in the water level inthe evaporating pan 2 over time. If the water level does not changewithin a certain amount of time or if its change exceeds apre-determined limiting value, the control means (not shown),cooperating with the floating switch 6, switches-off the evaporatingcylinder 10 and refrigerator drives 11.

All the features shown in the description, in the following claims andin the drawing may be essential to the invention either individually orcollectively in any arbitrary combination.

LIST OF REFERENCE NUMBERS

1 evaporating cylinder

2 evaporating pan

3 water bath

4 circumference

5 ice scraper

6 floating switch

10 transmission motor and drive.

11 refrigerator

What is claimed is:
 1. Flake ice machine comprising: a cylindricalevaporating cylinder; an electric drive means for rotating saidevaporating cylinder; an electrical refrigeration means for guidingcoolant through said evaporating cylinder; an evaporating pan foraccepting and containing water, said evaporating cylinder disposed insaid evaporating pan to rotate for wetting said evaporating cylinderwith water; means for removing the flake ice from a girth of theevaporating cylinder; electric control means communicating with saidelectrical drive means and said electrical refrigerator means; andsensor means for signaling said electrical control means and saidelectrical refrigerator means, said sensor means measuring a quantitydepending on a fill time of said evaporating pan, a thickness of an icelayer on said evaporating cylinder, and on a water level in saidevaporating pan, wherein said control means switches off saidrefrigerator means and said drive means when said measuring quantitydoes not change or when said measuring quantity exceeds predeterminedlimiting values.
 2. The flake ice machine of claim 1, wherein themeasuring value detected by said sensor means corresponds to a change ina water level in said evaporating pan with time.
 3. The flake icemachine of claim 1, wherein said sensor means comprises a floatingswitch disposed at said evaporating pan.